1. Field of the Invention
The present invention relates to a gas leakage detector.
More particularly the present invention concerns an improvement in a handy, portable and electronized gas leakage detector capable of detecting a very small amount of gas leakage and indicating detection by changing the manner of lighting an alarm lamp and/or sounding a buzzer.
2. Prior Art
Hitherto, several types of gas leakage detectors have been proposed, but most of them, for example a flame ionization detector, are large and of stationary types which can not be used handily, for example by a single hand. Therefore such apparatuses are not generally usable as portable apparatus by servicemen. Accordingly, a simple conventional method of a gas leakage detection has been using a detection liquid, such as a solution of soap to form bubbles at the gas leakage, but its limit of detection is about 5.times.10.sup.-4 cc/sec.
Furthermore, even if the conventional apparatus is capable of measuring a small concentration of leaking gas, the conventional apparatus having an amperemeter or seven-element figure indicators to indicate the measured concentration is not actually useful in finding location of the gas leakage, since the operator of the apparatus has to carefully watch both the indicator and a position of the gas leakage to be detected. And accordingly, pulsated sound alarm or pulsated light alarm type solid state electronized gas detector has been proposed, but the conventional electronized detector still have two problems. First, they require a long warm-up time. Second, changes in pulsation frequency may go unobserved or produce erroneous indications, particularly at high and low frequencies.